Chris Kelly, the former Facebook executive who is facing a tough race for California attorney general, is taking aim at his past employer by blasting the social network’s new privacy policies.

In an e-mail to members of the progressive organization MoveOn, Kelly said he is “troubled” that Facebook plans to share users’ data with third-party websites “without clear consent.”

“That’s why I’m joining MoveOn in calling for Facebook to reiterate its commitment to privacy by sharing user information only with prior approval from users,” he said in the e-mail Thursday. He also posted the e-mail on his Facebook page.

His criticism of Facebook comes near the end of an intense political battle with six other candidates vying for the Democratic nomination in Tuesday’s primary. Kelly has already spent about $4 million of his own money on the campaign.

He has stiff competition from candidates who already have experience holding public office, including San Francisco District Attorney Kamala Harris, former Los Angeles City Attorney Rocky Delgadillo, and Assemblymen Ted Lieu, Alberto Torrico and Pedro Nava.

Kelly became Facebook’s chief privacy officer in 2005, just as the social network was starting to take off on college campuses. Since resigning to campaign ahead of Tuesday’s primary, Kelly has tried to distance himself from his Facebook identity. He’s taken some heat from rivals for being known as the public face of the company during several privacy flaps.

Siding with MoveOn on the site’s privacy issues is an about-face for Kelly, who went head-to-head with the organization in 2007 when it sharply criticized Facebook for its Beacon feature, which broadcast users’ online purchases to their friends.

MoveOn launched an anti-Facebook campaign to protest Beacon, calling it a significant breach of privacy. With Kelly at the helm, Facebook removed the Beacon feature and apologized to its users.

Facebook, the biggest social network with 400 million users, again came under pressure when it recently began sharing profile information with other sites across the Web without first getting users’ consent. Last week, Facebook responded by streamlining its privacy settings to make it easier for users to completely opt out of that type of information sharing activity.

“The early reaction to these changes from users around the world and the community of privacy and consumer groups has been overwhelmingly positive,” a Facebook spokesman said.

Kelly says the latest problems developed after his departure from the company and he is pushing Facebook to ask for users’ permission before sharing their information.

Kelly worked on Bill Clinton’s presidential campaign and was later a policy adviser for the White House Domestic Policy Council before returning to Silicon Valley. He’s made frequent trips to Washington over the past year to take part in privacy discussions on Capitol Hill and to attend fundraisers thrown for him by old friends in the Clinton administration.

Despite his disapproval of Facebook’s current privacy policies, Kelly has touted his experience in forging partnerships with all 50 state attorneys general to create safeguards to protect children from sexual predators online.

Kelly’s Facebook background has also helped him leverage his online social network to generate grass-roots support. His profile lists 20,260 fans.